Tester Site
August 06, 2021
Please Note This website is a tester for page layout and data visualization for the Lipp Lab COVID Wastewater monitoring project. The data on this page are not peer-reviewed or finalized for public release and thus should not be interpreted as such. If you are interesed in viewing the final data from this project please visit this website.
This dashboard provides weekly updates of SARS‑CoV‑2 (the virus that causes COVID‑19) levels in wastewater for Athens-Clarke County (ACC). Wastewater sampling can detect viruses that may be shed in feces from infected people within an entire community, including those that are presymptomatic and asymptomatic. This offers a method of estimating trends in community-scale circulation of COVID‑19 that does not rely on clinical or surveillance testing of individuals. Although we cannot currently use wastewater-based testing to estimate a specific number of people infected in a community, it can be used to understand trends and to anticipate potential increases in cases.
Navigating this site:
• Data Trends: Total viral load and trend analysis for the combined ACC area
• Individual Plants: Viral load and trend analysis for each plant and associated service area
• All Data: Concentration of SARS‑CoV‑2 gene targets by date and treatment plant
• Research Overview: Details on methods and approach
Data Trends
The trendline below reflects the estimated total viral load of SARS‑CoV‑2 in the combined sewershed of Athens-Clarke County (the service area for all three plants) (top chart) over time. The daily number of newly reported COVID‑19 cases in Athens-Clarke County (purple bars) appear alongside the 7-day moving average of new cases (yellow line) (bottom chart). We are using these data to estimate how changes in the concentration of SARS‑CoV‑2 in wastewater may reflect the community trends of circulating COVID‑19 infections.
Note about chart and methods.
The viral load estimated is based on the average concentration of the SARS‑CoV‑2 gene copies per liter of wastewater (as determined by the N1 and N2 viral nucleocapsid genes) x the total flow of wastewater over the sampling day. Both genes target the SARS‑CoV‑2 genome but have slight differences in how they perform in our tests; therefore, we are averaging them to simplify the interpretation of the viral load. The trend lines were calculated using locally estimated scatterplot smoothing (LOESS, span = 0.6). The error associated with these estimates (the 95% confidence interval) is displayed as the shaded area.
Weekly Data Update
Updated every Friday
Please Note: We strive to get results for each week’s sampling updated by 5:00 pm on Friday however, to ensure quality of data occasional delays in the update may occur. We will post updated data as soon as we are able.
August 2 & 4
Key Weekly Update: For the fifth week in a row, SARS‑CoV‑2 viral load increased across Athens-Clarke county. Levels for the week reached the 58th percentile for all samples collected to date; we are now in the upper half of viral load estimates and at levels we have not observed since April. This corresponds with rising reported cases which reached a 7-day running average of 36 cases per day as of Friday, 8/6 (up from 20 last Friday, 7/30). Last year, wastewater viral load began increasing in the second week of August, coinciding with the arrival of students to Athens before the UGA fall term. This year viral load and cases are rising earlier, but with imminent increase in population we anticipate a continued increase in viral transmission within the county. Considering this, we strongly encourage any residents/students who have not been vaccinated to do so in the near future.
August 2
SARS‑CoV‑2 viral RNA increased at all three area plants. Average concentrations (for the N1 and N2 gene targets) were >200,000 copies per liter at all plants, and reached >830,000 copies per liter at WRF B (west of Milledge Ave.).
August 4
SARS‑CoV‑2 detection from Wednesday’s samples were similar to those found on Monday, with concentrations all exceeding 200,000 copies per liter.
July 28 & 28
Key Weekly Update: Viral loads have increased steadily in the county’s wastewater over the past four weeks. Viral RNA was readily detectable in all wastewater samples collected on Monday 7/26 and Wednesday 7/28. For the week, viral load reached the 42nd percentile for all samples collected to date, climbing from the 31st percentile last week. These observations indicate increased viral shedding and circulation of SARS‑CoV‑2 in the community. Likewise, case reports have increased to a 7-day running average of 20 new cases per day (as of 7/29). This is the highest running average reported since March 2021. Rates of positive PCR tests were consistently above 10% for the week. Clarke county vaccination rates have remained near 39% for the past several weeks.
July 26
SARS‑CoV‑2 viral RNA was detectable in all wastewater samples collected on Monday, 7/26. The viral load increased slightly at WRF A and WRF B, but decreased at WRF C compared to collections from July 7/21. Viral concentrations exceeded 100,000 copies per liter at all plants and reached ~200,000 copies per Liter at WRF B.
July 28
Viral concentrations estimated for Wednesday, July 7/28 were similar to samples collected Monday, 7/26 for WRF A and C (at >100,000 copies per liter). Viral concentrations continued to increase at WRF B and reached ~500,000 copies per Liter).
July 19 & 21
Key Weekly Update: SARS‑CoV‑2 viral RNA increased for the third week in a row at all plants Total viral load for Athens-Clarke county is still in the lower one third of all samples collected to date (beginning June 2020) but load has increased from the 5th percentile for samples collected during the last week of June to the 31st percentile for samples collected this week. This indicates a persistent increase in viral load and circulation of SARS‑CoV‑2 in the community, which is consistent with increasing case reports (7-day running average of 10 new cases per day as of Friday 7/23/2021). Rates of positive PCR tests reached 8.1% (7-day running average as of 7/23) but testing numbers continue to be low (~134 tests per day for the week).
July 19
SARS‑CoV‑2 RNA was detected at all plants for the Monday collection. Levels at WRF B were similar to last week but virus loads increased substantially at both WRF A (UGA, downtown, and north Athens) and WRF C (eastside). Concentrations at WRF C reached >280,000 viral copies per liter and >125,000 copies per liter at WRF A.
July 21
Viral load was steady for WRF A and C on Wednesday July 21, compared to the Monday sample. However, concentration increased by 4-fold at WRF B (west of Milledge Ave.) from ~50,000 copies per liter on 7/19 to >200,000 copies per liter on 7/21.
July 12 & 14
Key Weekly Update: This week, SARS‑CoV‑2 viral RNA was readily detected in all wastewater samples. The average total viral load was comparable to the viral load recorded last week, on July 12, 2021. The 7-day running average has increased to 8 new cases per day (reported on 7/15/2021). Case positivity is 3.4%, while testing has dropped to 65 tests conducted per day (based on a 7-day average).
July 12
SARS‑CoV‑2 viral RNA was detected in all wastewater samples collected across WRF A, WRF B, and WRF C on Monday, July 12, 2021. Viral concentrations were highest at WRF A, at 165,000 copies per Liter. Concentrations were comparable at WRF B and WRF C, at ~45,000 copies per Liter.
July 14
SARS‑CoV‑2 Viral RNA was detected across all samples, again, on Wednesday July 14, 2021. Viral concentrations were comparable between samples and ranged from 20,000 copies per Liter to 50,000 copies per liter. The total viral load, averaged between all samples, was comparable to the viral load reported last week.
July 7
Key Weekly Update: SARS‑CoV‑2 viral loads in wastewater have increased, compared to last week’s samples. This increase in viral load corresponds with a marked increase in the number of reported cases this week. The 7-day running average in reported cases as risen to 7 new cases per day (reported on 7/8/2021). Case positivity has increased to 6.7%, while testing still remains low with a 7-day average of 84 tests conducted per day.
July 7
Wastewater this week was sampled on Tuesday July 6th, 2021. SARS‑CoV‑2 viral RNA was detected in all wastewater samples. Viral concentration was greatest at WRF C (~115,000 copies per L), as was the total viral load (8 x 10^11 copies). Viral concentration and total load were comparable between WRF A and WRF B. Results this week correspond with the observed increase in the number of reported cases in Athens-Clarke County.
June 2021
Key Weekly Update: This week, levels of SARS‑CoV‑2 decreased below the limit of detection in all but one sample collected. Levels at WRF A were detectable on 6/30/2021, but were below the limit of detection in all samples on 6/28/2021. Reported cases in Athens ended the week at 2 new cases per day, based upon the 7-day running average. Testing rates still remain low, with approximately 109 tests per day and a 1.5% test positively rate.
June 30
Viral levels were below the limit of detection at WRF B and WRF C. SARS‑CoV‑2 viral RNA was detected at WRF A at a concentration of approximately 24,000 copies/L.
June 28
After last week’s spike in viral load, SARS‑CoV‑2 RNA fell below the limit of detection in wastewater collected from all three WRF in Athens-Clarke County.
Key Weekly Update: SARS‑CoV‑2 loads in Athens-Clarke County increased this week, largely attributable to new detections of viral RNA at WRF B (area roughly west of Milledge Ave.) and continued detection at WRF C (east side) on both sampling days (levels at WRF A were below the limit of detection). Concentrations exceeded 500,000 copies per liter at WRF B on both sampling days after being below the limit of detection for 2 of the past 3 weeks (and 5 of the last 6 samples). Reported cases in Athens ended the week at 3 new cases per day (7-day running average), a slight increase compared to the prior week; however, testing rates are very low (~109 PCR tests per day).
June 23
Detection rates and levels were similar to the Monday sample, with >600,000 copies per liter (and both gene targets detected) at WRF B and >60,000 copies per liter (N1 gene only) at WRF C.
June 21
SARS‑CoV‑2 RNA was detected at both WRF B (both N1 and N2 genes) and WRF C (N1 gene only). Concentrations exceeded 840,000 copies per L at WRF B and 140,000 copies per liter at WRF C. This was the first detection at WRF B since June 7.
Key Weekly Update: Averaged for both sampling days this week and all plants, SARS‑CoV‑2 load was similar to the prior week; however after two weeks of samples below the limit of detection, viral RNA was detected at WRF C (covering Athens east side) on both sampling days. No viral RNA was detected at WRF B and was only detected on Monday at WRF A. Reported cases in Athens declined to a 7-day running average of 1.7 new cases per day (as of 6/18). 37% of residents of Athens-Clarke County are considered to be fully vaccinated.
June 16
Levels were below the limit of detection at both WRF A and WRF B but continued at detectable levels at WRF C. Concentrations exceeded 90,000 copies per L and both N1 and N2 gene targets were detected.
June 14
SARS‑CoV‑2 RNA was detected at both WRF A (N2 gene only) and WRF C (N1 gene only). Concentrations exceeded 23,000 copies per L at WRF A and 348,000 copies per L at WRF C. This was the first sample since May 24 in which viral RNA was detected at WRF C.
Key Weekly Update: On average for the week, SARS‑CoV‑2 concentrations remained low but were detected in samples from at least one plant on both sample days. Reported cases for Athens Clarke County were similar to last week and averaged 2.4 new cases per day (7-day average) as of 6/11. 33% of residents of Clarke County are considered to be fully vaccinated.
June 9
SARS‑CoV‑2 levels continued below the limit of detection for WRF C, marking the second week with no detection at this plant. Levels fell below the limit of detection at WRF B. At WRF A, concentrations increased to >640,000 copies per liter (both N1 and N2 genes).
June 6
Viral RNA was detected at WRF B (N1 gene target only) at an average concentration of ~135,000 copies per liter; no virus was detected at WRF A or C.
Key Weekly Update: After stable to declining SARS‑CoV‑2 levels in local wastewater for the past month, concentrations fell below the limit of detection at all three plants on both sample dates this week. While we cannot rule out presence of virus at levels below the detection capacity of our tests, these results do show that levels across the county are historically low. This is consistent with declining reported cases in Athens-Clarke County, which reached a 7-day average of 1.7 new cases per day as of Friday 6/4.
June 2
Samples collected Wednesday, 6/2, continued to show levels of SARS‑CoV‑2 RNA below our limit of detection.
June 1
Due to the Memorial Day holiday, samples were collected on Tuesday 6/1 (representing a composite sample between 6:30 am Monday 5/31 and 6:30 am Tuesday 6/1). Wastewater flows were low, especially at WRF A, suggesting a lower wastewater load over this holiday period. SARS‑CoV‑2 levels were below the limit of detection at all plants.
May 2021
Key Weekly Update: SARS‑CoV‑2 levels in Athens-Clarke County wastewater remain low with average loads for the week stable or slightly declining. This is consistent with declining reported cases in the county (3 new cases per day [7-day running average] as of 5/28, with a test positivity rate of 1.8%). 31% of Athens-Clarke County was considered to be fully vaccinated as of 5/28.
May 26
Loads at all plants declined from that observed on Monday (5/24). Levels fell below the limit of detection at both WRF A and WRF C, and at WRF B declined from 66,500 copies/L on 5/24 to 32,500 copies/L on 5/26.
May 24
SARS‑CoV‑2 virus was detectable at all three WRFs on Monday with loads increasing at both WRF A and C but declining at WRF B compared to the prior sample. For all plants combined, the total viral load remained below the 20th percentile of all samples.
Key Weekly Update: Average weekly viral loads have remained relatively stable in Athens-Clarke County over the past four weeks. As of 5/21/2021, reported cases in Clarke County averaged 5 new cases per day, based on the 7-day running average. Although testing volume is low, the 7-day positive test rate was 2.7%; 30% of Athens-Clarke county was considered to be fully vaccinated.
May 19
On Wednesday 5/19/2021, viral levels fell below the limit of detection for WRF C and continued below detection limits at WRF A. WRF A includes the entire UGA campus and this might reflect changes in residential population in that catchment. After falling below detection limits at WRF B on Monday, there was a notable increase in viral detection on Wednesday with the highest load noted since mid-April and a concentration >500,000 copies per liter.
May 17
On Monday 5/17/2021, viral levels fell below the limit of detection for both WRF A and WRF B. Total viral load at WRF C was comparable to the load estimated for the previous collection on 5/12/2021, but concentrations reached >100,000 copies per liter.
Key Weekly Update: Averaged across the two samples collected, SARS‑CoV‑2 levels reported this week are comparable to average levels reported for the past two weeks. Stability in viral levels reflect the stability in reported cases over the past two weeks. As of 5/13/2021, reported cases in Athens-Clarke county averaged 7 new cases (7-day running average), with a 7-day positive test rate of 4% (up slightly from last week); 29% of Athens-Clarke county was considered to be fully vaccinated.
May 12
SARS‑CoV‑2 viral RNA was detectable at all three facilities on Wednesday 5/12. Viral concentrations at each plant increased compared to samples collected 5/10, and ranged from ~23,000 copies per liter at WRF B to ~49,000 copies per liter at WRF C.
May 10
The total viral load on Monday (5/10) was slightly elevated compared to the viral load from the previous sample collected Wednesday, 5/5. SARS‑CoV‑2 viral RNA was detectable at WRF A and WRF B but fell below the limit of detection at WRF C.
Key Weekly Update: SARS‑CoV‑2 levels for the county declined for the second week in a row. For the week, the decline in daily load was noted at all three WRFs. Reported cases in Athens-Clarke county ended the week at 9 new cases per day (7-day running average) and a 7-day positive test rate of 3.4%, similar to reports for the prior week. As of 5/7/2021, 28% of Athens-Clarke county was considered to be fully vaccinated.
May 5
Viral loads were below the limit of detection at both WRF A and C, and increased slightly at WRF B. Averaged for all plants, the load declined compared to the Monday (5/2) sample. It is worth noting that wastewater flows were elevated at all plants after the heavy rainfall on Monday and Tuesday. This could have led to some dilution of the incoming sewage that, in turn, could dilute the viral signal.
SARS‑CoV‑2 RNA was detected at all three plants but at lower levels than noted for the prior sample date (4/28/2021). Viral concentrations ranged from ~23,000 genome copies per liter at WRF C to ~69,000 copies per liter at WRF A.
April 2021
Key Weekly Update: Average viral load declined slightly for the first time in 5 weeks. Average daily load was down at both WRF B and C but increased slightly at WRF A. Daily reported cases in Athens-Clarke County ended the week at 8 (7-day running average), after reaching recent high of 13 new cases per day (7-day average) on 4/19.
April 28
Viral loads for the Wednesday sample increased at all plants, compared to 4/26 (concentration >100,000 copies per liter), but to a lesser extent than has been observed in recent weeks. The 7-day running average of new cases in Athens-Clarke county was 10 on 4/28 with a positive test rate of 3.3% (7-day running average).
April 26
SARS‑CoV‑2 levels at all plants declined compared to the prior sample date (Wednesday, 4/22) but were not as low as had been noted in the prior few weeks’ Monday samples. Viral RNA was detected at all plants with concentrations > 50,000 genome copies per liter. On 4/26, GA DPH reported a 7-day running average of 9 new cases per day and a positive test rate of 3.7% (7-day running average).
Key Weekly Update: Viral load results this week look very similar to those noted last week. We observed a large difference between low loads for the Monday sample (4th %-ile), with levels below the limit of detection at WRFs A and C, followed by high loads on Wednesday (80th %-ile). Averaged for the week, levels for all plants combined were similar to last week’s average. This continued trend suggests that significant levels of SARS‑CoV‑2 continue to circulate in Athens-Clarke County, while reported cases have been relatively stable. This may be related to lower rates of testing across the area and potentially more asymptomatic infections (although without surveillance testing to confirm, this is only an assumption). GA DPH reports showed that daily cases ended the week at 12 (7-day running average) in Athens-Clarke County with a 7-day running average positive test rate of 4.8%, a slight increase from last week.
April 21
Viral loads increased at all plants, with the load at WRF B reaching its highest level since mid-January. Loads at WRFs A and C were similar (or lower) than that observed in last week’s Wednesday sample. On 4/21, GA DPH reported 10 new daily cases based on the 7-day running average and a PCR-test positivity of 4.2% (7-day running average).
April 19
SARS‑CoV‑2 loads and concentrations declined at all three plants for the sample collected Monday 4/19. Levels were below the limit of detect for WRFs A and C and were detectable, but low, at WRF B. This pattern of low levels on the Monday sample has been common in recent weeks; we are still evaluating additional to data to explain this trend. On 4/19, DPH reported 13 new cases per day using the 7-day running average. The reported test positivity rate reached 10.5% (5.3% based on the 7-day running average).
Key Weekly Update: Averaged for the week and across all plants, viral loads were slightly higher but comparable to the prior week’s average. However, there was considerable variability between sampling days this week, with levels below the limit of detection at two plants (A and C) on Monday before reaching high levels on Wednesday (Monday’s samples were in the 3rd percentile for load while those on Wednesday reached the 77th percentile for load). The 7-day running average of new cases per day ended the week at 10 (4/16). The 7-day running average of positive PCR tests in Athens-Clarke county (reported to DPH) was 4%, a decline from the prior week.
April 14
Viral levels increased substantially on 4/14, reaching over 1 million genome copies per liter at each plant and the highest daily load (all plants combined) since late January.
The 7-day running average of newly reported cases was 10 as of 4/14 and the 7-day running average of positive PCR tests increased to 4.1% for the county.
April 12
SARS‑CoV‑2 levels were below the limit of detection at WRFs A and C but remained stable at WRF B. Rainfall throughout the day Sunday may have contributed to some loss of signal in the wastewater samples, but we have observed over the last month that the detection of virus in the sample collected on Monday is often low for WRF A in particular which may suggest some variability in the wastewater flow over the weekend. This is something that we will be working to investigate.
The 7-day running average of newly reported cases was 9 as of 4/12 and the 7-day running average of positive PCR tests was 3.7% for Athens-Clarke county (per DPH).
Key Weekly Update: Viral RNA levels were comparable to those reported last week. While the total viral load remains relatively low (in the lower third of all concentrations reported) for Athens-Clarke County, a general upward trend has been observed over a period of three weeks. The 7-day running average of reported cases has increased to 12 cases per day as of 4/9 and the rate of positive tests increased to 5% (compared to 4% positivity on 4/2). These trends suggest that there is a continued need for preventative measures as vaccine distribution increases within the county.
April 7
SARS‑CoV‑2 viral RNA levels fell below the limit of detection at WRF A, but viral loads at WRF B and WRF C were comparable to observations on Monday (4/5). The running average number of new cases on 4/7 increased to 11.
April 5
Levels of SARS‑CoV‑2 viral RNA were detectable at all three WRFs. The viral load at WRF A increased slightly compared to the previous observation on 3/31. The viral loads at WRF B and WRF C were comparable to those observed in the previous week. The 7-day running average of new cases on 4/5 was 9.
March 2021
Key Weekly Update: Averaged for the week, SARS‑CoV‑2 viral RNA levels increased for the second week in a row across the Athens-Clarke County wastewater treatment plants. Average levels increased at all three plants, with moderate increases for the week at WRFs A and B and a substantial increase at WRF C. Although total viral load in wastewater across the area remains relatively low (in the bottom third fraction compared to all samples collected to date), the shift toward increasing levels over the last two weeks (after several weeks of stable to declining levels) is concerning. As of April 2, reported cases remained low in Athens-Clarke County, at 8 new cases per day (7-day running average), but the number of tests administered has declined and the percentage of positive tests has increased slightly (from 3% positive on 3/24 to 4% positive on 4/2 7-day running average). This illustrates the need for continued preventative measures as vaccine distribution increases within the county.
March 31
Levels declined (WRF B) or remained stable (WRF C), compared to the Monday sample, but increased substantially at WRF A.
March 29
SARS‑CoV‑2 RNA levels declined below the limit of detection at WRF A, but increased at both WRF B and WRF C compared to the prior sample date. The uptick at WRF C is notable because this plant had been below the limit of detection for the two prior weeks and reached a total load that we have not observed since late February.
Key Weekly Update: SARS‑CoV‑2 viral RNA levels remain low (very near the limit of detection) across the Athens-Clarke County area. Levels remained below current detection limits at WRF C (both collection days) and WRF A (Monday collection) but were detectable at WRF B. Daily case reports continue to be low across the county (7-day running average of 10 new cases per day or 8/100,000 people). As testing declines, the importance of wastewater based testing may become important to catch potential upticks in infection, but as of now, wastewater levels continue to be reduced.
March 24Viral RNA was again below the limit of detection at WRF C but was found at both WRF A and B. The concentration at WRF A was 133,507 genome copies per liter and at WRF B was 42,707 genome copies per liter.
March 22
SARS‑CoV‑2 RNA remained below the limit of detection at WRFs A and C but increased to an average concentration of 134,180 genome copies per liter at WRF B.
Mar 15 & 17
Key Weekly Update: For the first time in our reporting, SARS‑CoV‑2 levels dropped below our current detection limit at all three plants, for both gene targets, on both 3/15 and 3/17.
What this means
SARS‑CoV‑2 shedding has declined substantially across Athens Clarke County, but we cannot assume that the virus is completely absent from wastewater. Our current method of analysis has a high limit of detection, which means that SARS‑CoV‑2 is very likely still present in wastewater (and in the community) but is at a concentration that our current method cannot detect. However, the drop is in line with falling case reports, which reached a 7-day running average of only 8 new cases per day by the end of the week (a level we have not observed since June 2020, before the summer peak).
We are working on methods to increase our limit of detection as we enter a phase in the pandemic where hopefully cases continue to decline and vaccine coverage increases.
Key Weekly Update: The total viral load of SARS‑CoV‑2 in wastewater continues to remain stable. Average total loads for each week have been oscillating around 10^13 total copies, since the week beginning 2/14.
March 10
Viral estimates for Wednesday 3/10 were highly variable between plants. Compared to Monday’s samples, the viral load increased considerably at WRF B. However, the viral load decreased at WRF A, and remained stable at WRF C. The variability between plants and sample dates is common, as the levels of virus drop close to or below the limit of detection for our method.
The 7-day running average of newly-reported cases was 15.
March 8
The viral load estimated for WRF A and WRF C on Monday 3/8 was comparable to the estimates from the previous collection, on Wednesday 3/3. The total viral load at WRF B dropped 10-fold between the two collection periods. The total viral load for the county was comparable to the load observed in the previous weeks, dating back to 2/14.
The 7-day running average of newly-reported cases was 24.
Key Weekly Update: Total viral load in wastewater continues to remain stable. With average loads for each week changing little since the week of 2/14. Also similar to our observations for the past three weeks, there was considerable variability between plants and between sampling dates, which may be more common as concentrations of the SARS‑CoV‑2 RNA approach the limit of our detection capabilities. Wastewater results suggest persistent viral shedding in the community but at levels well below their peak in January.
March 3
Viral levels increased overall in samples collected on Wednesday 3/3, with SARS‑CoV‑2 detected at all three plants, bringing total load in line with what we have observed since early to mid February.
The 7-day running average of newly reported cases increased to 28 (following a single day report of 64 new cases on 3/3).
March 1
Samples for Monday 3/1 were highly variable between plants. After falling below our limit of detection the prior week (Wednesday 2/24), levels at WRF A reached >300,000 copies per liter. However, levels at both WRF B and C fell below the limit of detection (for both targets) for the first time since early November.
The 7-day running average of newly reported cases was 21.
February 2021
Key Weekly Update: Overall, the viral load in Athens-Clarke County wastewater averaged for the week was comparable to last week’s average load. However, there continues to be wide variability of viral levels in our wastewater samples. The 7-day running average of reported cases was 22 as of 02/25/2021.
February 24
The total viral load estimated for Wednesday 2/24 declined sharply from previous observations. The positivity rate of our collection has declined; SARS-CoV-2 was only detectable in only two of our wastewater samples.
The 7-day running average of newly reported cases in Athens was 21 per day on 2/24.
February 22
Total viral load on Monday 2/22 was comparable to the viral load estimated for the previous collection, Wednesday 2/17. While there was an increase in viral load at WRF A, viral levels declined at WRF B and WRF C.
The 7-day running average of newly reported cases in Athens dropped to 21 per day on 2/17.
Key Weekly Update: On average for the week, viral load in Athens-Clarke County wastewater declined for the fourth week in row. However, there was a wide variability between the two collection dates with very low levels on Monday offset by substantially higher loads on Wednesday. Rainfall this week likely resulted in dilution of viruses in wastewater. Newly reported cases reached a 7-day running average of 28 as of 02/19/2021.
February 17
Viral load for all plants increased relative to the Monday sample. No samples were below the limit of detection for either gene target and average concentrations increased relative the prior sample. It is yet not clear if this indicates a shift in trend or if this was an outlier sample.
7-day running average of newly reported cases reached 30 on 2/17.
February 15
Total viral load (all plants combined) declined sharply in the samples collected on Monday 2/15. This trend was evident at both WRF A and B with more stable levels at WRF C. Concentrations were below the limit of defection at WRF A, but this is very likely due to dilution effects.
The 7-day running average of newly reported cases in Athens dropped to 34 per day on 2/15.
Key Weekly Update: Total viral load in Athens-Clarke County wastewater declined for the third week in row, reaching levels that we have not observed since early December. These declines are similar to those observed in new reported daily cases for the county, which have declined to a 7-day running average of 37 as of Friday 2/12.
February 10
Viral load for all plants combined continued to decline from the Monday sample. Again, this decline was driven largely by a lower load at a single plant (WRF A), with WRF B and C levels similar to that noted on Monday. The N1 target was below the limit of detection in the WRF A sample.
7-day running average of newly reported cases reached 43 on 2/10.
February 8
Total viral load (all plants combined) declined slightly relative to the prior sample (collected 2/3). The decline was primarily driven by lower loads at WRF C with relatively stable levels at WRFs A and B. Additionally, the N2 target was below the limit of detection at WRF C.
The 7-day running average of newly reported cases in Athens dropped to 44 per day on 2/8.
Key Weekly Update: Total viral load continued to decline this week, making this the second week of decline following record high levels in mid-January. While the total viral load may be declining, shedding (and transmission) of SARS‑CoV‑2 remains active and it is important to maintain health and safety practices. Newly reported cases in Athens-Clarke County ended the week (2/5) at a 7-day running average of 51.
February 3
Viral load for Tuesday 2/2 through Wednesday 2/3, was virtually unchanged from the Monday sample.
7-day running average of newly reported cases was 58 on 2/3.
February 1
Viral load (1/31 – 2/1) across the three treatment plants combined declined by ~50% compared to the prior sample last week. Declines were noted at all plants. Additionally, the N2 target was below the limit of detection at one site. This is the first week that we have not seen 100% positivity for both gene targets since early December.
January 2021
Key Weekly Update: The average viral load for the week decreased from the previous week but was still higher than 70% of all samples collected to date. Note that estimates for viral load may be underestimated, due to a significant amount of rainfall during this collection period (1/27). The 7-day average of newly reported cases ended the week (1/29) at 82. Viral load and transmission remain high in Athens-Clarke County.
January 27
Viral load for the period between Tuesday 1/26 and Wednesday 1/27 was comparable to the viral load estimated from Monday’s collection. It is important to note that Wednesday’s sampling period coincided with a major rain event in the Athens area. Infiltration of stormwater into the sewer system may dilute viral concentrations of wastewater. Sample positivity remains high (100%) and concentrations reached over 1 million copies per liter.
The 7-day moving average for reported cases was 78 for 1/27/2021.
January 25
The total viral load for Sunday 1/24 through Monday 1/25 decreased compared to the previous week’s observations. SARS‑CoV‑2 was detected from all wastewater samples (positivity rate of 100%).
The 7-day moving average for reported cases was 74 for 1/25/2021.
Key Weekly Update: Averaged for the week, total viral load continues to be high (exceeding the load in 90% of samples analyzed to date). Much like the pattern noted last week, the two samples varied substantially with the 1/19 sample reaching extremely high levels and declining the following day. This week the variability between the two days appears to be driven primarily by large changes at particular plants (especially WRF A). Overall, the average total load this week is similar to last week, changing by only 5%. Case reports in Athens-Clarke County declined this week, which follows the declines in sewage levels noted in our 1/4 report. Wastewater observations from the last two weeks suggest that shedding of the virus has increased and may not yet be apparent in case reports.
January 20
Total viral load for the sample collected between 1/19 and 1/20 declined compared to the prior day sample. This is similar to the pattern noted last week as well; however, the decline was not consistent across all three plants. Viral load at WRF C (including East Athens) increased approximately 4-fold reaching a similar level noted the prior week (on 1/11). Levels at the other two plants declined or were stable.
The 7-day running average of reported cases in Athens Clarke County further declined to 73 by 1/20.
January 19
Over the 24 h period of collection (6:30 am Monday 1/18 – 6:30 am 1/19), the total viral load at all three plants combined reached the second highest level in our data set (falling only slightly behind the load for 1/11, one week ago). The load increased to the highest level recorded at WRF A (including north Athens, downtown, and UGA), where average concentration exceeded 10 million copies per liter. Little change was observed at WRF B and WRF C compared to levels on 1/13.
The 7-day running average of reported cases in Athens Clarke County declined to 81 on 1/19.
Key Weekly Update: The average viral load for the week was among the highest in our sample collection (exceeding the viral load for >94% of samples to date). This was driven by very high counts in Monday’s (1/11) sample. The 7-day average of newly reported cases ended the week (1/15) at 105. Viral load and transmission remain high in Athens-Clarke County.
January 13
Viral load for the period between Tuesday 1/12 and Wednesday 1/13 declined from the all-time high noted in Monday’s sample. The decline in load was noted in all treatment plants but sample positivity remains high (100%) and concentrations reached over 3 million copies per liter.
The 7-day moving average for reported cases was 108 for 1/13/2021.
January 11
Total viral load for Sunday 1/10 through Monday 1/11 increased by 5-fold compared to levels measured the week prior, reaching the highest recorded total viral load through the course of this study. Concentrations increased at all three plants, exceeding 4 million copies per liter. The rate of increase and total load are similar to the trends noted in early to mid-August around the start of the UGA fall semester. These results may reflect an acceleration of new infections, the increase in population (and possible carriers) with the arrival of students for the start of the UGA spring term, or both.
The reported 7-day moving average of clinical cases in Athens-Clarke County increased to 107 on 1/11.
January 4
Total viral load for Sunday 1/3 through Monday 1/4 decreased slightly compared to levels measured the week prior, although detection rate remains high (all samples from all plants for both the N1 and N2 gene have been positive since 12/14/2020).
Reported cases in Athens-Clarke County increased from a 7-day running average of 46 on 12/28/2020 to 84 on 1/4/2021. Although total viral load is currently steady or declining, the current rise in reported cases that began on 12/28 was preceded by 3 weeks of increasing viral load in wastewater (which peaked on 12/21/2020)
Note from the team:
We apologize for the delay in data updates over the last couple of weeks. Critical supplies for our analyses were back ordered and then delayed in shipping. We are now back up and running and working to process our backlog. We will aim to get back to timely updates by next week. One benefit of this short break was that we were able to take some much-needed time to look back critically at our last 30 weeks of work, which has been difficult to do while also in the crunch to get samples processed and analyzed. We reanalyzed the full data set and conducted an intense QA/QC. You will see some slight changes in the charts on the dashboard that reflect this new analysis. We thank you for sticking with us through what has become a much longer effort than any of us imagined.
Key Weekly Update: Total SARS‑CoV‑2 viral load decreased slightly for the second week in row, while case reports continue to climb. Levels in wastewater are a real time estimate of viral shedding, and therefore may be out of sync with the timing of case reports, which often lag because of bias toward symptomatic infections and the time between testing and reporting. This current trend could suggest stabilizing case levels, which may not yet be apparent in the clinical reports. However, our total positivity rate for samples remains at 100%, which indicates that viral shedding (and likely transmission) remain high.
December 2020
December 28
Total viral load for Sunday 12/27 through Monday 12/28 declined by ~10-fold. This decline was observed across all three treatment plants and ends the 3-week trend of rising viral load at WRF C.
The 7-day running average of reported cases was 54 as of 12/30, which has held steady for the past 10 days (declining from 61 on 12/21).
December 21
Total viral load was comparable to observations from the previous week. Viral load continues to increase at WRF C, continuing a 2+ week trend. These data suggest that there is consistent viral shedding, but stable transmission within the community.
As of 12/21 there was an average of 61 new daily cases (7-day running average).
Key Weekly Update 12/14-12/16: The total viral load detected from wastewater for the week of 12/14/2020 continued to increase compared to previous observations; 12/16/2020 marks the highest level observed since August.
December 16
Total viral load for Tuesday 12/15 through Wednesday 12/16 increased to the highest observed level since early August. Total load increased at all three plants, and was especially notable at WRF C, which reached its highest load and concentration to date. This suggests a continued rise in reported cases is likely in the coming days.
The 7-day running average of reported cases as of 12/16 was 62.
December 14
Total viral load for Sunday 12/13 through Monday 12/14 was consistent with those observed last week, suggesting consistent but stable transmission within the community.
As of 12/14 there was an average of 58 new daily cases (7-day running average). Athens-Clarke county has reported an average of 54 - 58 new cases per day since 12/5.
Key Weekly Update 12/7-12/9: Total viral loads for the week of 12/07/2020 have increased compared to the prior week; coupled with clinical data, increased viral levels indicate active transmission in the community.
December 9
Total viral load for Tuesday 12/8 through Wednesday 12/9 remains consistent with the increasing trend observed on 12/7. Coupled with an increase in newly reported COVID‑19 cases, increasing levels of SARS‑CoV‑2 in wastewater suggest an increase in viral transmission within the community.
December 7
The total viral load has increased compared to estimates from the previous week. This increase corresponds with the overall increasing trend in viral load over the past several weeks. Coupled with an increase in newly reported COVID‑19 cases (seven day running average of 56), these data suggest an increase in viral transmission within the community.
Key Weekly Update 11/30-12/2: Total viral loads for the week of 11/30/2020 declined compared to the prior week; however, levels continue to indicate active transmission in the community.
Site update announcement
Starting this week (Nov 30 & Dec 2 sampling) we will be reporting our SARS‑CoV‑2 wastewater viral load data as a single metric to improve comprehension. Viral load data will be reported as the average of the N1 and N2 gene targets detected using our assay. Concentration values for both targets will still be reported independently in the “All Data” tab. We feel that this is an easier to understand presentation of the data and is supported after considering 30 weeks of data collection.
December 2
Concentrations of SARS‑CoV‑2 viruses were similar between the 12/2 sample and that collected on 11/30. However, overall viral load declined slightly across the area, with the exception of WRF C, where viral load has been steady to increasing.
As of 12/03/2020, the 7-day running average of new cases in Athens Clarke County reached 39, which is higher than we have observed since September. As we have noted before, viral levels in wastewater general precede case reports in the community. The uptick in cases this week follows elevated viral loads in sewage that we noted last week.
November 2020
November 30
Total viral load for Sunday 11/29 through Monday 11/30 was similar to that noted last week. Of note, this sample collection period included periods of heavy rain on Sunday, which resulted in infiltration of rainwater into sewer lines. This leads to higher than normal volumes entering the treatment plants and diluting of the sewage. Not surprisingly, we noted a decline in the concentration (number of viral copies per liter) because of this dilution (see ‘All Data’), but our estimation of total viral load (total viral copies present) accounts for this effect by correcting for the higher volume. Therefore, total viral load remains high despite the lower concentration.
As of Monday 11/30, the 7-day average of new cases in Athens Clarke County remained at 30. However, on Wednesday 12/2 the county reported 78 new cases, which is the largest single day report since 9/16 (80 cases).
November 25
The increasing trend observed on 11/23 continued through 11/25 suggesting an increase in SARS‑CoV‑2 transmission compared to the prior weeks of sampling. This increase was not observed in the reported clinical cases which have remained steady at approximately 29 cases per day for the past two weeks.
November 23
The levels of SARS‑CoV‑2 have increased approximately 10-fold from the previous sampling period (November 18, 2020). It is too to soon to predict if the increase in SARS‑CoV‑2 levels indicates in increase in transmission. If there is increased transmission, we would expect to see this same trend in our next sampling period (November 25, 2020).
The 7-day running average of newly reported cases has remained stable for the last 2 weeks (ranging between 27 and 32 new cases per day).
November 18
There was little change in the SARS‑CoV‑2 concentrations and total load for the sample collected on 11/18. Levels were comparable to those measured on 11/16 and in the previous week. Good agreement was observed in the estimation of both the N1 and N2 gene targets.
Daily reported cases remain at a seven-day average of 32.
November 16
For the Monday sample this week (collected between 6:30 am Sunday 11/15 and 6:30 am Monday 11/16). We observed increased concentrations of SARS‑CoV‑2 at all plants based on the N1 gene; concentrations (copies per L) increased by >80% since the November 11 sample. However, the N2 gene target was below the limit of detection for all plants. We observed a similar divergence on 11/04 and we are continuing to evaluate the performance of both assays. On balance, the data suggest a slight but consistent increasing trend.
The 7-day running average of daily reported cases in Athens-Clarke County is 31 as of 11/17, similar to that reported last week, after several weeks of reported cases in the low 20s.
November 9 & 11
This week, 24-hour composite samples were collected on Monday 11/9 and Wednesday 11/11. Total daily load estimates for the week show stable to increasing levels. WRF A loads increased modestly on 11/9 with little change by 11/11. At WRF B, estimated loads declined to the limit of detection on 11/9 but increased to >500,000 copies per liter for both gene targets by 11/11. WRF C loads increased through both sampling dates. Of note, both gene targets were detected this week, with notable increases in the N2 gene (which was largely below the limit of detection last week).
The 7-day running average of daily reported cases (PCR confirmed) in Athens-Clarke County has increased slightly in the last week to an average of 31 cases per day as of 11/12.
Site update announcement:
Beginning November 2, 2020, data from all three plants is being reported on this site. Data summaries have been updated to include the third plant (WRF C) back to July 5, 2020. Therefore, charts for ‘data trends’ and ‘all data’ may vary slightly from previously posted reports because of this inclusion; although, in part because WRF C is small compared to the other two plants, trends changed little with this update.
Going forward, we will begin sampling twice weekly at the three WRFs with support from Athens-Clarke County. We will update this site with any anticipated changes in timing of our data reporting.
November 2 & 4 data update: This week, we are reporting concentrations of SARS‑CoV‑2 in wastewater collected from two sampling events (~6:30 am Sunday Nov 1 to ~ 6:30 am Monday Nov. 2 and ~6:30 am Tuesday Nov. 3 to ~6:30 am Wednesday Nov. 4, 2020). The increased sampling frequency is intended to improve the resolution of our data.
This week, there was a notable difference in the trends based on the two gene targets, with viral gene copies attributed to the N1 gene increasing slightly (especially at WRF B) or staying steady and viral gene copies attributed to the N2 gene declining (with most samples at or below the limit of our detection). Detection rates of the two genes can vary, especially in wastewater; therefore, it is important to consider results of these targets together. In combination, we think that these results suggest SARS‑CoV‑2 loads are stable or may be declining
The 7-day running average of reported cases (PCR confirmed) in Athens-Clarke County has remained steady at 22 - 24 new cases per day.
October 2020
October 27
Concentrations of SARS‑CoV‑2 in Athens-Clarke County wastewater are comparable to those reported during the previous week (October 20, 2020). Concentrations are also similar between the two plants. These data suggest that there may be persistent viral shedding throughout the community. Reported cases in Athens-Clarke County have been stable over the past three weeks, with a 7-day running averages of 20-24 cases per day.
October 20
SARS‑CoV‑2 concentrations in Athens-Clarke County wastewater showed a consistent upward trend this week. WRF A continued its increase from the prior week with concentrations reaching as high as 1 million copies per L. Concentrations at WRF B increased from the below the limit of detection to >300,000 copies per L. The continued upward trends may suggest changes in viral shedding within the community.
Reported cases in Athens-Clarke County have been stable over the week, with a 7-day running average of 20-30 cases per day.
October 13
Trends in SARS‑CoV‑2 concentrations in Athens wastewater were split this week between the two sampled plants. During the collection period (Oct 12 – 13), viral RNA concentrations at WRF B declined to at or below the limit of detection. However, levels at WRF A increased to >500,000 copies per L, after declining to near the limit of detection the prior week. It is too early to know if the increased SARS‑CoV‑2 signal at WRF A is indicative of possible uptick in transmission or due to inherent variability in sample collection. If there is increased transmission, we would expect to see the trend in wastewater continue next week as well as an increase in reported cases.
Reported cases in Athens-Clarke County have remained stable for the last 2 weeks (7-day running average between 21 and 24 new cases per day.
October 6
Levels of SARS‑CoV‑2 continue to decrease in wastewater samples collected from Athens-Clarke County. These results are consistent with the decrease in the number of newly-reported cases over the past two weeks.
It is important to note that the levels of SARS‑CoV‑2 virus have decreased to or at the limit of detection for our current method. Our theoretical limit of detection is approximately 3,570 copies/L. Below this concentration, viruses may be not be detected or quantified with accuracy.
September 2020
Sept 29
Overall SARS‑CoV‑2 concentrations continued to decline in sewage reaching Athens’s WRFs, in line with decreasing reported cases in Athens-Clarke County. The decline was especially evident at WRF A, where levels were at or below the limit of detection for our methods. However, concentrations at WRF B were virtually unchanged from last week.
With our current process, we cannot accurately detect virus concentrations below about 3,000 copies per L. Therefore, we cannot assume that a sample that is ‘below the limit of detection’ is negative for SARS‑CoV‑2, rather it may be at some level that we cannot accurately determine with our current method. Our lab is evaluating different detection options that may improve detection during times with lower levels of circulating virus.
Sept 22
Concentrations of SARS‑CoV‑2 declined this week in wastewater collected from both WRFs. Average levels remain above 100,000 copies/L. This decline is consistent with declines in reported cases in Athens-Clarke County.
Sept 15
This week, the level SARS‑CoV‑2 continued to exceed 1 million copies of virus per liter of sewage. While the 7-day running average of new cases has declined in Athens-Clarke County, there were no significant changes in the level of SARS‑CoV‑2 virus in wastewater, compared to those observed on September 9, 2020.
Sept 8
This week, levels of SARS‑CoV‑2 for both targets at both plants continued to exceed 1 million copies of virus per liter of sewage. Average values were similar to concentrations from the prior week (September 1, 2020) with virtually no change in the average levels at WRF B and a 6% reduction at WRF A.
An important note about sample collection this week was that it occurred over the Labor Day holiday and may explain the slight reduction in viral concentration at the WRF A plant. Samples were collected between ~6:30 am Monday through 6:30 am Tuesday. The volume of wastewater flowing into WRF A decreased from 5.73 million gallons on September 1, 2020 to 4.96 million gallons on September 8, 2020. The collection area for WRF A includes the UGA main campus and Downtown Athens. We suspect that this week’s data point reflects the real-time effect of population movement on viral levels in wastewater. In other words, a closed campus and likely large number of people traveling reduces the input. Samples collected on a particular day reflect the inputs of that day and not necessarily the entire week.
Our trend analysis suggests a continued elevation in total viral load (see data trends tab).
Daily reported cases in Athens-Clarke County continue to rise, now reaching a 7-day moving average of 126.1 new cases per day.
Sept 1
This week continues the trend of the past month with SARS‑CoV‑2 concentrations increasing in wastewater. Levels increased to their highest point since the beginning of data collection with average concentrations for both plants and both targets exceeding 3 million copies of virus per liter of sewage, approximately 10-fold higher than the prior week. Daily reported cases in Clarke County also continued to rise reaching a 7-day moving average of >74 cases per day.
August 2020
Aug 25
SARS-CoV-2 concentrations in Athens-Clarke County wastewater increased slightly in this week’s samples (reaching >900,000 copies of the virus per liter of sewage). This moderate increase continues the upward trend observed over the prior three weeks. Reported cases have remained steady through the week (8/18 - 8/25/2020) averaging ~30 new cases per day.
Aug 28
On August 18, 2020, the concentration of SARS‑CoV‑2 increased to over 100,000 copies per liter for both gene targets. This uptick is somewhat reflected in the daily reported cases for Athens-Clarke county and may indicate further increases in the coming weeks.
Furthermore, this week marks the return of approximately 30,000 undergraduate students to the UGA main campus for the start of the fall semester.
Prior to Aug 18, 2020
Weekly analyses of SARS‑CoV‑2 in sewage began June 16, 2020, at which time concentrations were below the current method limit of detection and new cases were reported at <10 per day. Reported cases began to increase to >20 per day in late June and SARS‑CoV‑2 concentration increased to up to 10 million viral copies per liter. Sewage concentrations were steady through mid-July inline with newly reported cases averaging 35 per day. Beginning July 21, 2020 SARS‑CoV‑2 concentrations in sewage began to decline through early August, while concurrent case report remained high. We suspect that this decline possibly preceded the decline in cases noted in late August, which may be due to lags in testing results and case reporting.
Since August 4, 2020 SARS‑CoV‑2 concentration has steadily increased for both the N1 and N2 gene targets. This suggests that sewage concentrations may be a leading indicator for new cases in the community, but more data collection and monitoring of delays in testing reports will be needed to confirm this trend.
Individual Plants
Three plants service the Athens-Clarke County region. WRF A serves the largest portion of the community (including all of UGA main campus and downtown Athens), followed by WRF B (including areas west of Milledge Ave.), and WRF C (including Athens Eastside). Total capacity at WRF C is substantially smaller than the other two plants; this plant also receives periodic waste from pumped septic system and ‘port-o-potties’, which may lead to increased variability over time. Load and trends over time are shown for each service area. Trend analyses follow the same procedure as noted in ‘Data Trends’ tab.
Sewershed Map
Sewershed map of Athens-Clarke County
WRF A
WRF B
WRF C
